Email List Normalizer Online - Lowercase, Deduplicate and Sort
Normalize an email list by splitting common separators, lowercasing, validating, deduplicating and sorting addresses.
About this tool
Whitespace, commas and semicolons separate addresses. Every value is trimmed, converted to lowercase, checked with a basic email pattern and returned as one address per line.
How to use
- Enter the value in the format described by the tool.
- Run the conversion or calculation in your browser.
- Review and copy the generated result.
Features
- Accepts several common separators.
- Removes exact duplicates after lowercasing.
- Returns alphabetically sorted addresses.
Common use cases
- Clean newsletter export lists.
- Normalize copied recipient addresses.
- Prepare one-address-per-line input.
Common issues and tips
- The built-in pattern is a practical syntax check, not delivery verification.
- Lowercasing the local part follows common practice but some systems can treat it as case-sensitive.
Privacy
Processing runs locally in your browser. Input is not uploaded to Tools12345.
Frequently asked questions
Does it send a verification email?
No.
Which separators work?
Whitespace, commas and semicolons.
Are duplicates removed?
Yes, after converting addresses to lowercase.